This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Transcription is a basic, essential function that contered around the activity of a polymerase (often RNA polymerase II), but efficient transcription also requires the concerted efforts of numerous addition regulatory factors. These factors assist in various ways, for example by diminishing the physical barrier provided by the chromatin template as maintaining the appropriate post-translational modifications on the histones. The five subunit Paf1 complex is a transcription elongation factor that is required for the efficient transcription many genes, the maintenance of active chromatin modifications, and for proper 3'processing of RNA. It is not known how Paf1 coordinates these functions and there is little structural information or clues from sequence homology to direct our thinking about the mechanism of Paf1c function. We are hoping to gain insight into this through structural analysis of the Paf1 complex as well as isolated domains and complexes with various binding partners. The end goal is to develop an understanding of how Paf1c functions within the context of the transcription machinery.